1. Field of the Invention
The present invention relates generally to optical equipment, and more particularly to an adapter assembly suitable for mounting a video camera, or a video camera and 35-mm camera, to a medical microscope.
Medical and research microscopes frequently incorporate beam splitting assemblies to permit additional viewing, video, and camera attachment ports. Commonly available beam splitters provide a pair of optical attachment ports in addition to the primary viewing eye pieces.
In order to permit the attachment of more than one camera to a single optical port on a microscope beam splitter, the prior art has provide dual camera adapters which permit the attachment of both a video camera and a 35-mm camera to a single optical attachment port. Such dual video camera adapters are available commercially from suppliers such as Carl Zeiss, Inc., and are manufactured by Urban Engineering Company, Burbank, Calif.
While functional and useful, such conventional video adapters generally posses lenses which provide only one focal length for each of the video camera and 35-mm camera. Moreover, the video attachment receptacles are generally suitable for either a bayonet-type mount or for a C-type mount, but not both. Additionally, the dual camera adapters are generally capable of being mounted only on a particular brand of microscope Thus, a hospital or laboratory must posses numerous specific adapters in order to handle the various combinations of video camera, video camera magnification, 35-mm camera magnification, and brand of microscope employed.
A particular concern is the desire to provide different relative magnification for the video camera and 35-mm camera With present equipment, such a change in relative magnification requires that the entire video adapter be removed and replaced with a second video adapter in order to provide the necessary internal optics for the necessary focal length for each camera.
For these reasons, it would desirable to provide universal adapter systems which are capable of receiving a variety of different video cameras and/or 35-mm cameras and attaching said video and 35-mm cameras to different brands of microscope beam splitters. Such universal adapter systems should further provide for a wide range of different focal length magnifications for both the attached video camera and the attached 35-mm camera.
2. Description of the Background Art
Adapters for simultaneously mounting a video camera and a 35-mm camera on one side of a surgical microscope beam splitter are shown in U.S. Pat. Nos. 4,272,161 and 4,143,938. Such adapters are commercially available from Carl Zeiss, Inc., and manufactured by Urban Engineering Co., Burbank, California. Beam Splitters having integral video cameras are shown in U.S. Pat. Nos. 4,805,027 and 4,344,667. A beam splitter having three identical optical trains and four viewing stations is shown in U.S. Pat. No. 4,688,907. Automatic iris control systems for use with surgical microscope adapters are shown in U.S. Pat. Nos. 3,820,882 and 4,300,167. A zoom lens adapter for an endoscopic camera is shown in U.S. Pat. No. 4,781,448.